Endo Y, Miyai K, Iijima Y, Nakajima T, Eda Y, Fujita H, Unoki M
Department of Laboratory Medicine, Osaka University Medical School, Japan.
Acta Endocrinol (Copenh). 1989 Feb;120(2):201-9. doi: 10.1530/acta.0.1200201.
Epitope mapping of hTSH was carried out using 19 monoclonal antibodies prepared with hTSH or its beta-subunit as antigen. The affinity constants of the monoclonal antibodies ranged from 9.6 X 10(7) to 5.7 X 10(9) mol/l for hTSH. The binding activities of monoclonal antibodies were maintained or in some cases rather enhanced after removal of the sugar moiety of the subunits of hTSH, and completely diminished after reduction of intramolecular S-S bonds in the subunits of hTSH. Ten monoclonal antibodies recognized the epitopes on hTSH (alpha:beta subunit combined form) and on free alpha-subunit form. Eight other antibodies recognized the epitopes on free/or combined form of beta-subunit, all of which did not recognize any other human glycoprotein hormones. The monoclonal antibodies directed against the alpha-subunit could bind also other human glycoprotein hormones to a varying extent. On the basis of results from competitive binding studies, the antibodies directed against alpha-subunit and those against beta-subunit were each classified into five subgroups recognizing different antigenic determinants. The remaining one antibody recognized an epitope expressed only by hTSH and not by the free subunits. In addition, a positive cooperativity on the binding of hTSH was observed between monoclonal antibodies directed towards a particular epitope on the alpha-subunit and those towards a epitope on the beta-subunit. From these data, two-dimensional map of epitopes on hTSH was constructed. The epitopes on each subunit were found to form a cluster with complicated overlapping, suggesting a highly conformational structure.
以人促甲状腺激素（hTSH）或其β亚基为抗原制备了19种单克隆抗体，并对hTSH进行了表位作图。这些单克隆抗体对hTSH的亲和常数范围为9.6×10⁷至5.7×10⁹mol/L。去除hTSH亚基的糖基部分后，单克隆抗体的结合活性得以维持，在某些情况下甚至有所增强；而hTSH亚基分子内的S-S键还原后，结合活性则完全消失。10种单克隆抗体识别hTSH（α:β亚基结合形式）和游离α亚基形式上的表位。另外8种抗体识别β亚基游离/结合形式上的表位，它们均不识别任何其他人类糖蛋白激素。针对α亚基的单克隆抗体也能不同程度地结合其他人类糖蛋白激素。根据竞争性结合研究结果，针对α亚基的抗体和针对β亚基的抗体分别被分为五个亚组，它们识别不同的抗原决定簇。其余一种抗体识别仅由hTSH表达而不由游离亚基表达的表位。此外，在针对α亚基上特定表位的单克隆抗体与针对β亚基上一个表位的单克隆抗体之间，观察到了hTSH结合的正协同性。根据这些数据，构建了hTSH表位的二维图谱。发现每个亚基上的表位形成了一个具有复杂重叠的簇，表明其具有高度的构象结构。
